Treatment of tobacco



July 30, 1968 R. REMER 3,394,709

TREATMENT OF TOBACCO Filed April 135, 1964 I N VENTOR.

United States Patent 3,394,709 TREATMENT OF TOBACCO Robert K. Remcr, Evanston, IlL, assignor to Inca Inks, Inc., Evanston, Ill., a corporation of liliinois Filed Apr. 13, 1964, Ser. No. 359,257 3 Claims. (Cl. 131-121) This invention relates to a novel method of treating tobacco so as to polymerize at least a portion of the tarforming substances contained therein where-by when the tobacco is smoked, the tar content of the smoke is at least appreciably reduced.

Smoking tobacco is known to contain a complex mixture of substances as is well documented in the technical literature on this subject. When the tobacco is smoked, the resulting smoke contains an appreciable content of so-called tobacco tars derived from tar-forming substances in the tobacco leaf. These tars are present in tobacco smoke as colloidal liquid particulate matter. It has long been suspected that such tobacco smoke tars may contain cocarcinogens. The composition of tobacco and tobacco smoke has been discussed at length in Chapter 6 of the recent publication of the US. Department of Health, Education and Welfare entitled Smoking and Health, Report of the Advisory Committee to the Surgeon General of the Public Health Service (Public Health Service Publication No. 1103).

I have found that the tar-forming compounds found in tobacco leaves may be polymerized such as by exposure to polymerizing radiation, e.g. photopolymerization produceable from ultra-violet light. As a result of polymerization it appears that the polymerized substances are not present in the form of tobacco tars in the smoke but apparently remain in the ash or non-volatile residue. However, I have not yet had adequate opportunity to fully investigate and determine the relatively complex chemistry that is involved and ascertain fully and precisely the fate of the polymerized tar-forming substances.

The polymerization of the tar-forming substances is carried out with the tobacco immersed in a suitable liquid medium as hereinafter described. Various catalyst may be used to catalyse the reaction. Ceric ions and cinnomyl chloride ions will act as catalysts.

The object of my invention, generally stated, is a method of treating tobacco so as to alter or polymerize the tarforming compounds and at least substantially reduce the tobacco tars present in the smoke from the treated tobacco.

A further object of the invention is the provision of smoking tobacco that has been so modified by the treatment of the present invention that the tar content of the smoke therefrom is appreciably altered and substantially reduced.

Still another object of the invention is the provision of suitable apparatus for treating tobacco in accordance with the present invention whereby at least a substantial portion of the tar-forming substances therein can be efiiciently polymerized.

Certain other objects of the invention will, in part, be obvious and will in part appear hereinafter.

For a more complete understanding of the nature and scope of the invention, reference may now be had to the following detailed description thereof taken in conjunction with the accompanying drawing wherein:

The figure is a diagrammatic vertical sectional view through apparatus wherein my present invention may be practiced.

Referring to the drawing, a tank is indicated at which is provided on the bottom with a high frequency impulse generator 6, such as an ultrasonic generator commercially available from a number of sources. High frequency or ultrasonic energy is currently used in industrial cleaning equipment such as in connection with the de-greasers. The

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high frequency impulse units comprise a generator and a transducer. The purpose of the sonic generator is to subject the contents of the chamber 5 to high frequency energy or vibration. Tanks equipped with high frequency power units are commercially available from The Bendix Corporation, Davenport, Iowa and Multisonic Corporation, Westbury, New York.

The ultrasonic vibrations effect a rapid and deep penetration of the solvent or liquid medium, including any surfactants, catalytic or other substances present therein, into the interior of the tobacco particles bringin about intimate contact or association with the tobacco fibers and the tar-forming substances in the tobacco structure.

In carrying out my tobacco treatment I prefer to use a solvent or liquid medium having a relatively low boiling point yielding vapors that are heavier than air and easy to condense. The heat necessary to produce vaporization and boiling of the non-aqueous solvent or liquid may be provided by an electrical bank type heater 7 of known commerical type encircling the lower portion of the vessel or container 5.

In order to retain solvent vapor in the equipment the upper portion of the container 5 is provided with a condenser 8 in which cold water may be circulated, being introduced through the upper inlet connection 10 and discharged through the lower outlet connection 11.

The tobacco to be treated is first loaded into a basket 12 formed of wire or other foraminous material that sets in the container 5 and may be provided with lifting handles 13. The liquid level is indicated at 14 and the tobacco is indicated at 15.

Actinic radiant energy for producing photopolymerization of the tar-forming substances within the tobacco may be provided from ultra-violet lamps 17 mounted on a bar 16 suitably supported wthin the upper portion of the container 5. Several makes of ultra-violet lamps are commercially available which may be used for this purpose including those often referred to as sun, xenon, mercury vapor or quartz lamps. Other sources of radiant energy may be used including, cathode ray tubes, corona discharge generators, lasers, masers and sources of gamma and beta radiation. So-called solar furnaces may also be used where practical.

Among the solvents that may be used to advantage are methylene dichloride, perchloroethylene, trichloroethylene,

Chlorotene NU 1,1,l-trichloroethane, pentachloroethylene, ethylene dichloride, trichlorometh-ane, dichloromethane, trichlorotritluoroethane, trichloromon-ofluoromethane and hexane, and various mixtures thereof. So-called diphase systems may also be used. The liquid medium employed should preferably have a boiling point below that of water.

With the solvent boiling rapidly there will be efficient agitation of the tobacco leaves or particles 15 so that they are substantially and uniformly exposed to the ultraviolet irradiation discharge from the lamps 17. The high frequency generator 6 serves to produce cavitation within the tobacco leaves and thereby assists in the phot-opolymerization action on the tar-forming substances making the action more rapid and efficient.

As a further aid to the process I prefer to use and incorporate in the liquid or solvent medium various surfactants which cause the liquid to more rapidly wet and penetrate the tobacco leaves, particles and stems. The surfactants may be of the anionic, cationic or non-ionic variety. For example, the following may be used:

(a) Benax 2A0 (dodecylidiphenyl ether disulphonic acid) Dow Chemical C0. Anionic.

(b) G-330 0 Alkyl aryl sulfonate (Atlas Powder Co.)

Anionic. (c) Gafac -PE-510 (phosphate alkyl phenol esters of polyoxyethylenated alkylphenol) General Aniline. Anionic.

(d) Arquad 25 (Dialkyl dimethyl quaternary ammonium chloride) Armour Chemical. Cationic.

(e) Cetyl pyridinium chloride. Cationic.

While tobacco is normally negatively charged I have found that when a cationic surfactant is used in the present treatment the polarity or charge on the tobacco apparently will be reversed and it will become positively charged. I have not yet had an opportunity to fully explore the potential benefits which this change in electrostatic charge or polarity may contribute to the filtration of tobacco smoke. However, it is believed this change can be taken advantage of in providing more eflicient smoke filters.

The following example will serve to more fully disclose my invention.

Example Methylene chloride is used as the non-aqueous solvent or liquid in tank 5. It is heated to 104 F. at which temperature it boils rapidly. Sutficient cold tap water is run through the condenser 8 so that the vapors from the methylene chloride are substantially condensed so that there is little or no loss of vapor from the container 5. One ultra-violet lamp emitting ultra-violet in the 1,000 to 6,000 angstrom units range with concentration in the 2,530 A range is used for each gallon of solvent. The tobacco treated is ordinary cured tobacco and an ultrasonic generator 6 may be used having wave energy frequency of from 5,000 to 60,000 cycles/second and a wattage of from 50 .to 425 watts/square inch of transducer surface.

The tobacco is allowed to remain in the boiling solvent under exposure to the ultra-violet lamps for approximately 10 minutes. At the end of this time the basket 12 is slowly removed carrying with it the tobacco from which the liquid solvent readily drains and residue solvent rapidly volatilizes so that the tobacco becomes free or substantially free of solvent as the basket is lifted from the container. Any residual traces of vapor that may remain readily volatilize and disappear.

Smoke from cigarettes made with the treated tobacco and others made with the same tobacco untreated are lighted and the smoke therefrom passed through white filter paper. There is noticeably less dark brown stain deposited on the filter paper by the smoke from the cigarettes that contained the treated tobacco in comparison with the cigarettes having the untreated tobacco.

It will be apparent that a number of modifications may be made in the process and apparatus described above. For example, instead of having a batch process as described, the treatment can be carried out on a continuous basis through conveyorized treating apparatus. The methylene chloride solvent can be replaced by any one of the other specifically mentioned or by still others that would have comparable properties. The ultra-violet lamps 17 may be replaced by other sources of irradiation having the ability to polymerize the tar-forming substances in the tobacco. For example, corona discharge generators such as the Lepel and Mancib units may be used.

Various forms of transducers or sources of high frequency vibrations and energy may be employed and these may be either exteriorly or interiorly mounted.

By increasing the etficiency of exposure of the individual tobacco particles to the ultra-violet or other radiation the time of the treatment may be materially or proportionately reduced.

1 claim:

1. The method of treating tobacco to polymerize at least a portion of the tar-forming substances therein which comprises subjecting a quantity of tobacco to polymerizing radiation while the tobacco is immersed in a boiling liquid, said bath being subjected to high frequency vibrations.

2. The method of claim 1 wherein said high frequency vibrations are in the range of 5,000 to 60,000 cycles per second.

3. Tobacco treated in accordance with the method of claim 2.

References Cited UNITED STATES PATENTS 1,123,522 1/1915 Halle. 1,719,291 7/1929 Federmann 131-143 1,920,588 8/1933 Pacini 131-12l 2,048,624 7/1936 Roselius 131 143 2,108,305 2/1938 Coe 131-121 X 2,227,863 1/1941 Rhodes l3 l143 LUCIE H. LAUDENSLAGER, Primary Examiner. 

1. THE METHOD OF TREATING TOBACCO TO POLYMERIZE AT LEAST A PORTION OF THE TAR-FORMING SUBSTANCES THEREIN WHICH COMPRISES SUBJECTING A QUANTITY OF TOBACCO TO POLYMERIZING RADIATION WHILE THE TOBACCO IS IMMERSED IN A BOILING 